BACKGROUND: Approximately 43,000 new hepatitis B virus (HBV) infections occurred in 2007. Although hepB vaccination has been recommended for adults at high-risk for incident HBV infection for many years, coverage remains low.

METHODS: We used the 2009 National Health Interview Survey to assess self-reported HepB vaccine uptake (≥1 dose), series completion (≥3 dose), and independent predictors of vaccination among high-risk adults aged 18-49 years. High-risk adults were defined as those reporting male sex with men; injection drug use; hemophilia with receipt of clotting factors; sexually transmitted disease in prior five years; sex for money or drugs; HIV positive; sex with persons having any above risk factors; or who "felt they were at high risk for HIV". Persons with none of the aforementioned risk factors were considered non-high risk. Bivariate analysis was conducted to assess vaccination coverage. Independent predictors of vaccine uptake and series completion were determined using a logistic regression.

RESULTS: Overall, 7.0% adults aged 18-49 years had high-risk behaviors. Unadjusted coverage with ≥1 dose was 50.5% among high-risk compared to 40.5% among non-high-risk adults (p-values <0.001) while series completion (≥3 doses) was 41.8% and 34.2%, respectively (p-values <0.001). On multivariable analysis, ≥1 dose coverage, but not series completion, was higher (Risk Ratio 1.1, 95% CI=1.0-1.2, p-value=0.021) among high-risk compared to non-high risk adults. Other characteristics independently associated with a higher likelihood of HepB vaccination among persons 18-49 years included younger age groups, females, higher education, ≥2 physician contacts in the past year, ever tested for HIV, health care personnel, received influenza vaccination in the previous year, and ever received hepatitis A vaccination. Vaccine uptake with ≥1 dose increased by 5.1% (p=0.047) among high-risk adults between 2004 and 2009.

CONCLUSIONS: A small increase in ≥1 dose HepB vaccination coverage among high-risk adults compared with non-high risk adults was documented for the first time in 2009. Higher coverage among persons 18-30 years may reflect aging of persons vaccinated when they were children and adolescents. To improve protection against hepatitis B among high-risk adults, healthcare providers should offer hepatitis B vaccination to persons at high risk and those who seek vaccination to protect themselves and facilitate timely completion of the three (3) dose HepB series.